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Commit 9a6e5948 authored by Dave Martin's avatar Dave Martin Committed by Marc Zyngier
Browse files

arm64/sve: Move sve_pffr() to fpsimd.h and make inline 



In order to make sve_save_state()/sve_load_state() more easily
reusable and to get rid of a potential branch on context switch
critical paths, this patch makes sve_pffr() inline and moves it to
fpsimd.h.

<asm/processor.h> must be included in fpsimd.h in order to make
this work, and this creates an #include cycle that is tricky to
avoid without modifying core code, due to the way the PR_SVE_*()
prctl helpers are included in the core prctl implementation.

Instead of breaking the cycle, this patch defers inclusion of
<asm/fpsimd.h> in <asm/processor.h> until the point where it is
actually needed: i.e., immediately before the prctl definitions.

No functional change.

Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
Reviewed-by: default avatarAlex Bennée <alex.bennee@linaro.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 2cf97d46

arch/arm64/include/asm/fpsimd.h

+13 −0
Original line number Diff line number Diff line
@@ -18,6 +18,8 @@ 


#include <asm/ptrace.h>

#include <asm/errno.h>

#include <asm/processor.h>

#include <asm/sigcontext.h>



#ifndef __ASSEMBLY__
@@ -61,6 +63,17 @@ extern void sve_flush_cpu_state(void); 
/* Maximum VL that SVE VL-agnostic software can transparently support */

#define SVE_VL_ARCH_MAX 0x100



/* Offset of FFR in the SVE register dump */

static inline size_t sve_ffr_offset(int vl)

{

	return SVE_SIG_FFR_OFFSET(sve_vq_from_vl(vl)) - SVE_SIG_REGS_OFFSET;

}



static inline void *sve_pffr(struct thread_struct *thread)

{

	return (char *)thread->sve_state + sve_ffr_offset(thread->sve_vl);

}



extern void sve_save_state(void *state, u32 *pfpsr);

extern void sve_load_state(void const *state, u32 const *pfpsr,

			   unsigned long vq_minus_1);

arch/arm64/include/asm/processor.h

+11 −1
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ 


#include <asm/alternative.h>

#include <asm/cpufeature.h>

#include <asm/fpsimd.h>

#include <asm/hw_breakpoint.h>

#include <asm/lse.h>

#include <asm/pgtable-hwdef.h>
@@ -247,6 +246,17 @@ void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused); 
void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused);

void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused);



/*

 * Not at the top of the file due to a direct #include cycle between

 * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include

 * ensures that contents of processor.h are visible to fpsimd.h even if

 * processor.h is included first.

 *

 * These prctl helpers are the only things in this file that require

 * fpsimd.h.  The core code expects them to be in this header.

 */

#include <asm/fpsimd.h>



/* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */

#define SVE_SET_VL(arg)	sve_set_current_vl(arg)

#define SVE_GET_VL()	sve_get_current_vl()

arch/arm64/kernel/fpsimd.c

+0 −12
Original line number Diff line number Diff line
@@ -161,18 +161,6 @@ static void sve_free(struct task_struct *task) 
	__sve_free(task);

}





/* Offset of FFR in the SVE register dump */

static size_t sve_ffr_offset(int vl)

{

	return SVE_SIG_FFR_OFFSET(sve_vq_from_vl(vl)) - SVE_SIG_REGS_OFFSET;

}



static void *sve_pffr(struct thread_struct *thread)

{

	return (char *)thread->sve_state + sve_ffr_offset(thread->sve_vl);

}



static void change_cpacr(u64 val, u64 mask)

{

	u64 cpacr = read_sysreg(CPACR_EL1);